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Kernel: Some futex improvements

This adds support for FUTEX_WAKE_OP, FUTEX_WAIT_BITSET, FUTEX_WAKE_BITSET,
FUTEX_REQUEUE, and FUTEX_CMP_REQUEUE, as well well as global and private
futex and absolute/relative timeouts against the appropriate clock. This
also changes the implementation so that kernel resources are only used when
a thread is blocked on a futex.

Global futexes are implemented as offsets in VMObjects, so that different
processes can share a futex against the same VMObject despite potentially
being mapped at different virtual addresses.
This commit is contained in:
Tom 2020-12-21 23:21:58 -07:00 committed by Andreas Kling
parent 7581b64705
commit 1d621ab172
23 changed files with 928 additions and 63 deletions

View file

@ -45,10 +45,48 @@ int profiling_disable(pid_t);
#define THREAD_PRIORITY_HIGH 50
#define THREAD_PRIORITY_MAX 99
#define _FUTEX_OP_SHIFT_OP 28
#define _FUTEX_OP_MASK_OP 0xf
#define _FUTEX_OP_SHIFT_CMP 24
#define _FUTEX_OP_MASK_CMP 0xf
#define _FUTEX_OP_SHIFT_OP_ARG 12
#define _FUTEX_OP_MASK_OP_ARG 0xfff
#define _FUTEX_OP_SHIFT_CMP_ARG 0
#define _FUTEX_OP_MASK_CMP_ARG 0xfff
#define FUTEX_OP(op, op_arg, cmp, cmp_arg) \
((((op)&_FUTEX_OP_MASK_OP) << _FUTEX_OP_SHIFT_OP) | (((cmp)&_FUTEX_OP_MASK_CMP) << _FUTEX_OP_SHIFT_CMP) | (((op_arg)&_FUTEX_OP_MASK_OP_ARG) << _FUTEX_OP_SHIFT_OP_ARG) | (((cmp_arg)&_FUTEX_OP_MASK_CMP_ARG) << _FUTEX_OP_SHIFT_CMP_ARG))
#define FUTEX_OP_SET 0
#define FUTEX_OP_ADD 1
#define FUTEX_OP_OR 2
#define FUTEX_OP_ANDN 3
#define FUTEX_OP_XOR 4
#define FUTEX_OP_ARG_SHIFT 8
#define FUTEX_OP_CMP_EQ 0
#define FUTEX_OP_CMP_NE 1
#define FUTEX_OP_CMP_LT 2
#define FUTEX_OP_CMP_LE 3
#define FUTEX_OP_CMP_GT 4
#define FUTEX_OP_CMP_GE 5
#define FUTEX_WAIT 1
#define FUTEX_WAKE 2
int futex(int32_t* userspace_address, int futex_op, int32_t value, const struct timespec* timeout);
#define FUTEX_REQUEUE 3
#define FUTEX_CMP_REQUEUE 4
#define FUTEX_WAKE_OP 5
#define FUTEX_WAIT_BITSET 9
#define FUTEX_WAKE_BITSET 10
#define FUTEX_PRIVATE_FLAG (1 << 7)
#define FUTEX_CLOCK_REALTIME (1 << 8)
#define FUTEX_CMD_MASK ~(FUTEX_PRIVATE_FLAG | FUTEX_CLOCK_REALTIME)
#define FUTEX_BITSET_MATCH_ANY 0xffffffff
int futex(uint32_t* userspace_address, int futex_op, uint32_t value, const struct timespec* timeout, uint32_t* userspace_address2, uint32_t value3);
#define PURGE_ALL_VOLATILE 0x1
#define PURGE_ALL_CLEAN_INODE 0x2